In recreation vehicles (RV), also known as caravans, having toilets, a sewage-containing tank (often called a cassette tank, or a holding tank) are provided for storing sewage on-board the vehicle. Periodically the sewage-containing tank must be emptied. This is typically done at a campground by opening an outlet to the tank and allowing sewage from the tank to flow into a drain, a very unpleasant and often less than hygienic task.
According to the present invention a dump station for RV sewage-containing tanks, and a method of dumping sewage from such tanks, are provided which alleviate the unpleasantness associated with the tank dumping to some extent, and also do so in such a manner that a campground owner may provide this service without having to man the dumping facility. The invention is particularly useful for cassette tanks that are commercially manufactured by Electrolux and Thetford, and/or as shown in (or adapted from) U.S. Pat. Nos. 4,776,631, 4,944,048, and 5,031,249. However, the invention may be adapted to virtually any type of sewage-containing tank for an RV or caravan, such as the tanks illustrated in U.S. Pat. Nos. 5,621,924, 5,408,704, and 3,801,991, or DE 4003555.
According to one aspect of the present invention a dump station for RV sewage-containing tanks having an outlet, is provided. The dump station comprises: A container which can receive an RV sewage-containing tank, the container including a connector for making a substantially sealed engagement with the outlet of an RV sewage-containing tank received by the container. A flexible conduit connected to the connector, which conduit is capable of transporting sewage from the tank to a disposal location. And, means for mounting the container for movement between a first position in which the connector is generally horizontal, to a second position in which the connector is generally vertical and sewage from the tank may flow by gravity (typically primarily or substantially exclusively) through the container outlet into the connector and flexible conduit connected thereto so that the tank may be substantially drained of sewage.
The connector preferably comprises an inlet and an outlet, the inlet comprising a generally funnel-shaped flexible element of resilient material (e.g. natural or synthetic rubber or a resilient plastic). The dump station may further comprise a spray head mounted to the connector between the inlet and the outlet and positioned to effect spraying of liquid (preferably water, or water with a cleaning solution in it) through the connector into an RV tank received by the container. The spray head is preferably connected to a water conduit from a source of water under pressure, and a manually or preferably automatically operated valve is disposed in operative association with the conduit and spray head so that when the valve is opened liquid passes through the conduit to the spray head and is sprayed through the connector into an empty RV tank to be cleaned.
The container may comprise an open or openable (e.g. closed by a pivoting or sliding door) front end, a rear end comprising a rear wall which mounts the connector, and a bottom wall. The bottom wall may have slide tracks for guiding movement of the sewage-containing tank into the container, and a positive stop for stopping the penetration of the tank into the container at a position where the tank outlet has sealed with the connector.
The means for mounting the container may comprise any conventional structure which is capable of mounting the container so that it is safely and effectively movable between a position facilitating insert of the tank into the container, and a position where a tank within the container can drain sewage therefrom through the connector and the flexible conduit. While a wide variety of structures are suitable for this purpose, in one embodiment the mounting means comprises a pair of shaft stubs extending outwardly from side walls of the container to define a generally horizontal axis about which the container is rotatable from a first position in which the rear wall is substantially vertical, to a second position in which the rear wall is substantially horizontal. Stops may stop the container in the second position so that there is a slope of a few (e.g. about 2-3) degrees of the tank bottom (at that position), facilitating drainage of the sewage and cleaning liquid therefrom.
Rotation about the axis may be accomplished manually, or by powered elements (such as an electric motor, hydraulic or pneumatic cylinders, etc.). For example a first sprocket or pulley may be connected to one of the shaft stubs defining the axis of rotation, and a second sprocket or pulley may be mounted on a stationary support, the sprockets or pulleys connected together by a chain or belt. The second sprocket can be rotated either by a hand crank, or by a reversible motor or other powered element to slowly rotate the container (and tank within it) between the first and second positions, and then ultimately back to the first position. Preferably positive stops are provided on a stationary frame which limit the movement of the container to the first and second positions. The motor may be operable in response to a token or money (coin or bills) activated control. The flexible conduit may be connected up to a city sewage system, septic tank system, or any other suitable sewage treatment facility, while the conduit for the spray head is connected up to any suitable source of fresh water under pressure, such as a city water supply.
The entire structure described above may be mounted within a cabinet that has an open front end that can be opened or closed by a door, such as a metal roller blind.
According to another aspect of the present invention, a method of dumping sewage from an RV tank having an outlet and containing sewage, using a container having an outlet hose and an open or openable position, is provided. The method preferably comprises substantially sequentially: (a) Inserting the tank into the container through the open or openable position. (b) Effecting a substantially liquid-tight seal between the tank outlet and the container outlet hose. (c) Mechanically rotating the container about a substantially horizontal axis so as to cause sewage in the tank to flow through the outlet hose, out of the tank, to substantially empty the tank. (d) Mechanically rotating the container about the substantially horizontal axis back to a position for ready tank withdrawal. And, (e) withdrawing the tank from the container through the open or openable position.
The method preferably further comprises, after (c), (f) spraying a cleaning liquid into the tank to clean the inside of the tank, the liquid flowing out the outlet hose. The method is further defined so that (f) is practiced before (d) while the tank is positioned with the outlet near or at the bottom of the tank. In the practice of the method (c) and (d) may be practiced by utilizing a powered structure, and in response to a token or money-receiving actuator. In the method (b) is preferably effected substantially automatically by the practice of (a).
According to another aspect of the present invention a dump station is provided comprising the following components: A cabinet having an open front end which may be closed by a movable door. Disposed within the cabinet a container which can receive an RV sewage-containing tank, the container having an open or openable front end, a rear end to which an outlet hose is operatively connected, a bottom having tracks for receipt of an RV sewage-containing tank and a stop for stopping penetration of the tank into the container. The container mounted for rotation about a generally horizontally axis from a first position in which the rear wall is generally vertical, to a second position in which the rear wall is generally horizontal and sewage can flow out of the tank disposed within the container through the outlet hose. And, a spray head operatively connected to the rear wall of the container for spraying a cleaning liquid into a tank received by the container.
It is the primary object of the present invention to provide for the dumping of sewage from RV sewage-containing tanks in a procedure and utilizing an apparatus having enhanced functionality and hygiene. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.